<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Statement
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Sqlsrv.php 23775 2011-03-01 17:25:24Z ralph $
 */

/**
 * @see Zend_Db_Statement
 */
require_once 'Zend/Db/Statement.php';

/**
 * Extends for Microsoft SQL Server Driver for PHP
 *
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Statement
 * @copyright  Copyright (c) 2005-2011 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Db_Statement_Sqlsrv extends Zend_Db_Statement {
	
	/**
	 * The connection_stmt object original string.
	 */
	protected $_originalSQL;
	
	/**
	 * Column names.
	 */
	protected $_keys;
	
	/**
	 * Query executed
	 */
	protected $_executed = false;
	
	/**
	 * Prepares statement handle
	 *
	 * @param string $sql
	 * @return void
	 * @throws Zend_Db_Statement_Sqlsrv_Exception
	 */
	protected function _prepare($sql) {
		$connection = $this->_adapter->getConnection ();
		
		$this->_stmt = sqlsrv_prepare ( $connection, $sql );
		
		if (! $this->_stmt) {
			require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
			throw new Zend_Db_Statement_Sqlsrv_Exception ( sqlsrv_errors () );
		}
		
		$this->_originalSQL = $sql;
	}
	
	/**
	 * Binds a parameter to the specified variable name.
	 *
	 * @param mixed $parameter Name the parameter, either integer or string.
	 * @param mixed $variable  Reference to PHP variable containing the value.
	 * @param mixed $type      OPTIONAL Datatype of SQL parameter.
	 * @param mixed $length    OPTIONAL Length of SQL parameter.
	 * @param mixed $options   OPTIONAL Other options.
	 * @return bool
	 * @throws Zend_Db_Statement_Exception
	 */
	protected function _bindParam($parameter, &$variable, $type = null, $length = null, $options = null) {
		//Sql server doesn't support bind by name
		return true;
	}
	
	/**
	 * Closes the cursor, allowing the statement to be executed again.
	 *
	 * @return bool
	 */
	public function closeCursor() {
		if (! $this->_stmt) {
			return false;
		}
		
		sqlsrv_free_stmt ( $this->_stmt );
		$this->_stmt = false;
		return true;
	}
	
	/**
	 * Returns the number of columns in the result set.
	 * Returns null if the statement has no result set metadata.
	 *
	 * @return int The number of columns.
	 */
	public function columnCount() {
		if ($this->_stmt && $this->_executed) {
			return sqlsrv_num_fields ( $this->_stmt );
		}
		
		return 0;
	}
	
	/**
	 * Retrieves the error code, if any, associated with the last operation on
	 * the statement handle.
	 *
	 * @return string error code.
	 */
	public function errorCode() {
		if (! $this->_stmt) {
			return false;
		}
		
		$error = sqlsrv_errors ();
		if (! $error) {
			return false;
		}
		
		return $error [0] ['code'];
	}
	
	/**
	 * Retrieves an array of error information, if any, associated with the
	 * last operation on the statement handle.
	 *
	 * @return array
	 */
	public function errorInfo() {
		if (! $this->_stmt) {
			return false;
		}
		
		$error = sqlsrv_errors ();
		if (! $error) {
			return false;
		}
		
		return array ($error [0] ['code'], $error [0] ['message'] );
	}
	
	/**
	 * Executes a prepared statement.
	 *
	 * @param array $params OPTIONAL Values to bind to parameter placeholders.
	 * @return bool
	 * @throws Zend_Db_Statement_Exception
	 */
	public function _execute(array $params = null) {
		$connection = $this->_adapter->getConnection ();
		if (! $this->_stmt) {
			return false;
		}
		
		if ($params !== null) {
			if (! is_array ( $params )) {
				$params = array ($params );
			}
			$error = false;
			
			// make all params passed by reference
			$params_ = array ();
			$temp = array ();
			$i = 1;
			foreach ( $params as $param ) {
				$temp [$i] = $param;
				$params_ [] = &$temp [$i];
				$i ++;
			}
			$params = $params_;
		}
		
		$this->_stmt = sqlsrv_query ( $connection, $this->_originalSQL, $params );
		
		if (! $this->_stmt) {
			require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
			throw new Zend_Db_Statement_Sqlsrv_Exception ( sqlsrv_errors () );
		}
		
		$this->_executed = true;
		
		return (! $this->_stmt);
	}
	
	/**
	 * Fetches a row from the result set.
	 *
	 * @param  int $style  OPTIONAL Fetch mode for this fetch operation.
	 * @param  int $cursor OPTIONAL Absolute, relative, or other.
	 * @param  int $offset OPTIONAL Number for absolute or relative cursors.
	 * @return mixed Array, object, or scalar depending on fetch mode.
	 * @throws Zend_Db_Statement_Exception
	 */
	public function fetch($style = null, $cursor = null, $offset = null) {
		if (! $this->_stmt) {
			return false;
		}
		
		if (null === $style) {
			$style = $this->_fetchMode;
		}
		
		$values = sqlsrv_fetch_array ( $this->_stmt, SQLSRV_FETCH_ASSOC );
		
		if (! $values && (null !== $error = sqlsrv_errors ())) {
			require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
			throw new Zend_Db_Statement_Sqlsrv_Exception ( $error );
		}
		
		if (null === $values) {
			return null;
		}
		
		if (! $this->_keys) {
			foreach ( $values as $key => $value ) {
				$this->_keys [] = $this->_adapter->foldCase ( $key );
			}
		}
		
		$values = array_values ( $values );
		
		$row = false;
		switch ($style) {
			case Zend_Db::FETCH_NUM :
				$row = $values;
				break;
			case Zend_Db::FETCH_ASSOC :
				$row = array_combine ( $this->_keys, $values );
				break;
			case Zend_Db::FETCH_BOTH :
				$assoc = array_combine ( $this->_keys, $values );
				$row = array_merge ( $values, $assoc );
				break;
			case Zend_Db::FETCH_OBJ :
				$row = ( object ) array_combine ( $this->_keys, $values );
				break;
			case Zend_Db::FETCH_BOUND :
				$assoc = array_combine ( $this->_keys, $values );
				$row = array_merge ( $values, $assoc );
				$row = $this->_fetchBound ( $row );
				break;
			default :
				require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
				throw new Zend_Db_Statement_Sqlsrv_Exception ( "Invalid fetch mode '$style' specified" );
				break;
		}
		
		return $row;
	}
	
	/**
	 * Returns a single column from the next row of a result set.
	 *
	 * @param int $col OPTIONAL Position of the column to fetch.
	 * @return string
	 * @throws Zend_Db_Statement_Exception
	 */
	public function fetchColumn($col = 0) {
		if (! $this->_stmt) {
			return false;
		}
		
		if (! sqlsrv_fetch ( $this->_stmt )) {
			if (null !== $error = sqlsrv_errors ()) {
				require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
				throw new Zend_Db_Statement_Sqlsrv_Exception ( $error );
			}
			
			// If no error, there is simply no record
			return false;
		}
		
		$data = sqlsrv_get_field ( $this->_stmt, $col ); //0-based
		if ($data === false) {
			require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
			throw new Zend_Db_Statement_Sqlsrv_Exception ( sqlsrv_errors () );
		}
		
		return $data;
	}
	
	/**
	 * Fetches the next row and returns it as an object.
	 *
	 * @param string $class  OPTIONAL Name of the class to create.
	 * @param array  $config OPTIONAL Constructor arguments for the class.
	 * @return mixed One object instance of the specified class.
	 * @throws Zend_Db_Statement_Exception
	 */
	public function fetchObject($class = 'stdClass', array $config = array()) {
		if (! $this->_stmt) {
			return false;
		}
		
		$obj = sqlsrv_fetch_object ( $this->_stmt );
		
		if ($error = sqlsrv_errors ()) {
			require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
			throw new Zend_Db_Statement_Sqlsrv_Exception ( $error );
		}
		
		/* @todo XXX handle parameters */
		
		if (null === $obj) {
			return false;
		}
		
		return $obj;
	}
	
	/**
	 * Returns metadata for a column in a result set.
	 *
	 * @param int $column
	 * @return mixed
	 * @throws Zend_Db_Statement_Sqlsrv_Exception
	 */
	public function getColumnMeta($column) {
		$fields = sqlsrv_field_metadata ( $this->_stmt );
		
		if (! $fields) {
			throw new Zend_Db_Statement_Sqlsrv_Exception ( 'Column metadata can not be fetched' );
		}
		
		if (! isset ( $fields [$column] )) {
			throw new Zend_Db_Statement_Sqlsrv_Exception ( 'Column index does not exist in statement' );
		}
		
		return $fields [$column];
	}
	
	/**
	 * Retrieves the next rowset (result set) for a SQL statement that has
	 * multiple result sets.  An example is a stored procedure that returns
	 * the results of multiple queries.
	 *
	 * @return bool
	 * @throws Zend_Db_Statement_Exception
	 */
	public function nextRowset() {
		if (sqlsrv_next_result ( $this->_stmt ) === false) {
			require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
			throw new Zend_Db_Statement_Sqlsrv_Exception ( sqlsrv_errors () );
		}
		
		// reset column keys
		$this->_keys = null;
		
		return true;
	}
	
	/**
	 * Returns the number of rows affected by the execution of the
	 * last INSERT, DELETE, or UPDATE statement executed by this
	 * statement object.
	 *
	 * @return int     The number of rows affected.
	 * @throws Zend_Db_Statement_Exception
	 */
	public function rowCount() {
		if (! $this->_stmt) {
			return false;
		}
		
		if (! $this->_executed) {
			return 0;
		}
		
		$num_rows = sqlsrv_rows_affected ( $this->_stmt );
		
		// Strict check is necessary; 0 is a valid return value
		if ($num_rows === false) {
			require_once 'Zend/Db/Statement/Sqlsrv/Exception.php';
			throw new Zend_Db_Statement_Sqlsrv_Exception ( sqlsrv_errors () );
		}
		
		return $num_rows;
	}
	
	/**
	 * Returns an array containing all of the result set rows.
	 *
	 * @param int $style OPTIONAL Fetch mode.
	 * @param int $col   OPTIONAL Column number, if fetch mode is by column.
	 * @return array Collection of rows, each in a format by the fetch mode.
	 *
	 * Behaves like parent, but if limit()
	 * is used, the final result removes the extra column
	 * 'zend_db_rownum'
	 */
	public function fetchAll($style = null, $col = null) {
		$data = parent::fetchAll ( $style, $col );
		$results = array ();
		$remove = $this->_adapter->foldCase ( 'ZEND_DB_ROWNUM' );
		
		foreach ( $data as $row ) {
			if (is_array ( $row ) && array_key_exists ( $remove, $row )) {
				unset ( $row [$remove] );
			}
			$results [] = $row;
		}
		return $results;
	}
}
